In his book, A World Lit Only by Fire: The Medieval Mind and the Renaissance: Portrait of an Age, William Manchester devotes the majority of his book to an examination of the Reformation, but barely mentions the Renaissance. The fuzzy definition of the Renaissance allows this; in the right context and given the right explanation, almost all of the important aspects and figures of the Renaissance can also be included in the Middle Ages or the Reformation. Only in the realm of artistic expression was the Renaissance clearly defined, and since Manchester emphasized mainly the change of social, political, and theological thought, this clear part of the Renaissance was mainly excluded. The Renaissance was not a specific time, rather, it was the transition from the Middle Ages to the Reformation, somewhere in which one ends and the other begins.

Manchester's book grew out of an attempt to write an introduction to a friend's biography of Ferdinand Magellan. He planned to "provide the great navigator with a context, a portrait of his age." (xiv) Therefore, he traced the roots of Magellan's age to the Middle Ages, and he had to write through them, then to the Reformation, by way of the Renaissance. Magellan culminated a change in the way people thought about the world, and so Manchester's natural focus would not be on art history, but rather the change in thought from the "medieval mind" to Magellan's contemporaries. It seems to the reader that the Renaissance is hidden somewhere in the book, but that it cannot be pinned down. As Jackson Spielvogel stated in his book Western Civilization, "Whether the Renaissance represents the end of the Middle Ages or the beginning of a new era... is perhaps an irrelevant question." (360) The Renaissance's only distinct characteristic was its art, otherwise it was simply the transitional time and the process of that transition between the Middle Ages and the Reformation.

The Renaissance fades into existence at the very beginning of the fifteenth century, and is about over with the death of its most influential author, Desiderius Erasmus, in 1536 (Manchester, xi). At the beginning of this period, one still finds the identifying marks of the Middle Ages: the Black Death, omnipresent geographical isolation, massive crimes, and religious persecution. Some of these, particularly religious persecution, were not unique of the Middle Ages, but they continued in the same mode they had been in. And yet, even at this early stage, there are the beginnings of the Reformation: the birth of Humanism and formidable challenges posed on the established Catholic Church by branching groups, particularly the Hussites. John Wycliffe was already prodding the subject of transubstantiation and the material focus of the clergy before 1415 (Weber, 48), and the second-generation reformers were still stuck on the same arguments in the sixteenth century. Toward the end of the period, the Reformation was in full swing and had been going strong for twenty years. Humanists were vital to the creation of the religious Reformation, as well as opening doors in conjunction with other factors for artists and scientists. Artists represent the isolated Renaissance, but even deviant, challenging scientific thought was part of the Reformation. Thus we have an obscured Renaissance, so indistinct that one can barely call it a period, but rather an overlap of two others. This means that Manchester displays people who would otherwise be considered members of the Renaissance as players in the Reformation, and excludes the obvious Renaissance characters, as they are not involved with the main idea of his book.

In Manchester's book, it is only clear that he is speaking about the Renaissance in nine pages in an entire 300-page book, pages 86 through 94. On either side of these pages, and even within them, one finds the high Middle Ages and the Reformation mixed together into something called the Renaissance. Leonardo da Vinci and Nicolaus Copernicus are the main figures in these pages, along with an assortment of Renaissance artists. The artists were the unique ones, but even they were given the opportunity to change by the same sources that led to the Reformation: Humanism, decreasing control by the Church, social change, and even demographic change. The new intellectualism that gave the world the Renaissance artists also brought the religious reformers and new scientific mind that carried the Reformation along the path it took. Da Vinci was an artist, but also a scientist. He was not, however, a social commentator, a political revolutionary, or a religious arguer, and therefore did not have the drastic impact that Luther, Zwengli, and their Humanist teachers had. While the true Renaissance owed its existence to the Humanists and the theological changes they brought about, it is only clear that Manchester is writing about the Renaissance when he discusses the artists, because it is always possible to lump the other players in the Renaissance into either the high Middle Ages or the Reformation.

William Manchester's readers may find themselves lost in the pursuit of the Renaissance in his book. However, that is essentially because the Renaissance did not exist as a unique time period, a unique intellectual period, or a unique container of historical personalities. Instead, it was a rather an elusive mixture of epochs, somewhere in which the high Middle Ages ended and the Reformation began. Attempting to set the Renaissance apart from all other periods in history is impossible, because so many of its aspects are actually part of the Reformation or Middle Ages.